1. Field of the Invention
The present invention relates to a genomic DNA, more particularly, a genomic DNA encoding a polypeptide capable of inducing the production of interferon-xcex3 (hereinafter abbreviated as xe2x80x9cIFN-xcex3xe2x80x9d) by immunocompetent cells.
2. Description of the Prior Art
The present inventors successfully isolated a polypeptide capable of inducing the production of IFN-xcex3 by immunocompetent cells and cloned a cDNA encoding the polypeptide, which is disclosed in Japanese Patent Kokai No. 27,189/96 and 193,098/96. Because the present polypeptide possesses the properties of enhancing killer cells"" cytotoxicity and inducing killer cells"" formation as well as inducing IFN-xcex3, a useful biologically active protein, it is expected to be widely used as an agent for viral diseases, microbial diseases, tumors and/or immunopathies, etc.
It is said that a polypeptide generated by a gene expression may be partially cleaved and/or glycosylated by processing with intracellular enzymes in human cells. A polypeptide to be used in therapeutic agents should be preferably processed similarly as in human cells, whereas human cell lines generally have a disadvantage of less producing the present polypeptide, as described in Japanese Patent Application No.269,105/96. Therefore, recombinant DNA techniques should be applied to obtain the present polypeptide in a desired amount. To produce the polypeptide processed similarly as in human cells using recombinant DNA techniques, mammalian cells should be used as the hosts.
In view of foregoing, the first object of the present invention is to provide a DNA which efficiently expresses the polypeptide production when introduced into a mammalian host cell.
The second object of the present invention is to provide a transformant into which the DNA is introduced.
The third object of the present invention is to provide a process for preparing a polypeptide, using the transformant.
[Means to Attain the Object]
The present inventors"" energetic studies to attain the above objects succeeded in the finding that a genomic DNA encoding the present polypeptide efficiently expresses the polypeptide production when introduced into mammalian host cells. They found that the polypeptide thus obtained possessed significantly higher biological activities than that obtained by expressing a cDNA encoding the polypeptide in Escherichia coli. 
The first object of the present invention is attained by a genomic DNA encoding a polypeptide with the amino acid sequence of SEQ ID NO:1 (where the symbol xe2x80x9cXaaxe2x80x9d means xe2x80x9cisoleucinexe2x80x9d or xe2x80x9cthreoninexe2x80x9d) or its homologous one, which induces interferon-xcex3 production by immunocompetent cells.
The second object of the present invention is attained by a transformant formed by introducing the genomic DNA into a mammalian host cell.
The third object of the present invention is attained by a process for preparing a polypeptide, which comprises (a) culturing the transformant in a nutrient medium, and (b) collecting the polypeptide from the resultant culture.